1. Field of the Invention
The present invention relates to a cable reel and, more specifically, to a contact structure for cable reel, which keeps the contact plates in positive contact with the contact rings when the movable cable, which is connected to the contact plates, is turned relative to the fixed cable, which is connected to the contact ring.
2. Description of the Related Art
A cable reel, for example, a power cord reel is used to hold a power cord, enabling the power cord to be extended to a remote place. When a power cord reel is used, the electric plug of the power cord of the power cord reel is connected to power source, and then the power cord is extended out of the bobbin of the power cord reel, for enabling the power cord reel to be moved to the desired remote plate for the connection of an electric apparatus. The power cord reel has at least one electric socket for output of power supply. The at least one electric socket is located on the bobbin. When extending out the power cord, the at least one electric socket is rotated with the bobbin, preventing twisting of the conductors of the power cord. When using the power cord reel in this manner during raining, the at least one electric socket may be wetted, resulting in an electric leakage. In order to eliminate this problem, one electric socket of the power cord reel is connected to power supply by an electric cable, and then the power cord is extended out of the bobbin of the power cord reel and connected to an electric device at a remote place. When rotating the bobbin to extend out the power cord, the electric cable may be twisted and tangled. The power cord reel of a vacuum cleaner has the same problem.
The present invention has been accomplished under the circumstances in view. According to one aspect of the present invention, the contact structure comprises a fixed contact set, and a movable contact set. The fixed contact set comprises a stepped cap, the stepped cap having a plurality of annular steps of different diameters, and a plurality of contact rings of different diameters respectively mounted in the annular steps and respectively connected to the conductors of a fixed cable. The movable contact set comprises a stepped shaft rotatably inserted into the stepped cap of the fixed contact set, the stepped shaft having a plurality of steps corresponding to the annular steps of the stepped cap of the fixed contact set and a plurality of peripheral holes respectively formed in the steps, spring means mounted in the peripheral holes in the steps of the stepped shaft, and a plurality of arched contact plates respectively supported on the spring means in the peripheral holes and forced by the spring members into contact with the contact rings of the fixed contact set.
According to another aspect of the present invention, the stepped shaft comprises pairs of stop flanges respectively suspended in the peripheral holes in the steps thereof; the contact plates of the movable contact set each have two curved locating wings symmetrically disposed at two sides and respectively stopped against the stop flanges in the peripheral holes of the steps of the stepped shaft.
According to still another aspect of the present invention, the contact plates each have an inwardly curved guide flange disposed at a top side for guiding the movable contact set into movable connection with the fixed contact set.